Method of burning fuel and apparatus therefor



S. M EWEN March 2 1926. 1,575,350

METHOD OF BURNING FUEL AND APPARATUS THEREFOi? Filed April 9. 1923 OOOOOOQO 00000000" GOOOOOQQ OOOOOOOO www Patented Mar. 2, 1 926.

PATENT OFFICE.-

SAH'UEL HGEWEN, OF LONDON, ENGLAND, ASSIGNOR CBO INTERNATIONAL OOHBUS- TION ENGINEERING CORPORATION, OF NEW YORK, N. Y., K CORPORATION 01' namw aan. v

METHOD OF BURNING FUEL AND APPARATUS THEREFOR,

Application and April a 1923. Serial 110. 639,970.

To all whom it may camera:

Be it known that I, SAMUEL MQEWEN, a

' subject of the Kingof Great Britain, residequivalent layer. This is possible in a grate heated merely by radiation.

ing in London, England, have invented a certain new and useful Improved Method of Burning Fuel and Apparatus Therefor, of which the following is a specification.

Revolving cylindrical grates have been.

suggested as a means for keeping thefuel stirred and exposed to the air for combustion; the fuel was to be charged at one end of the cylinder and to be burnt by the air passing between the grate bars, the products of combustion passing from the end of the cglinder opposite the charging end..

Accor ing to the present invention fuel is burnt i the form of a cylindrical or of the above kind and-by the invention the fuel is distributed over the inner surface of the grate in the form of a cylindrical layer retained against the surface by centrifugal force owing to'the speed of revolution of the grate.

. One advantage of the invention is thatthe cylinder being lined with incandescent fuel the fuel forms an incandescent furnace arch for aiding the i 'tion of the incoming fuel, a function hit e rto performed by arches The difliculty of using the common brick arch with a revolvin cylindrical grate is one reason why suc grates have not come into use.

The invention is not limited to a cylindrical form of layer, that is tosay to a cylindrical grate; the form of any other suitable figure of revolution is equivalent, such as bearings. The fuel may be fed through such trunnion or other axial shaft carrying the grate; for instance, by means of a stationary or revolvin worm within the shaft.

The distrlbution of the fuel over the grate surface may be aided by imparting a-reciprocatingor other movement to the bars or f to some of them, for instance b' 'mountthese bars to slide 'longitudin of the 1D cylinder in guides under action 0 a cam or or to the chamber to be heated.

*the fuel is fed.

The grate is preferably contained in a casing to which air is charged under pressure and the gaseous products leaving the cylinder in axial direction am to the boil- In some applications it may be desirable to use a fanwheel to be rotated co-axially with the revolving grate, and placed sothat the fan blades move in the space between the periphery of the grate and the casing enclosing it. n

The accompanying. drawings illustrate a construction accordmg to the invention. Fig; 1 being a vertical longitudinal section through a furnace having 'acylindrical grate, Fig. 2 is a front elevation of the urnace, parts having been broken away; a is a perforated metal drum to each end of which is fixed a cast iron ring 6, 0. The

external periphery of each ring constitutes a roller path and is supported on two rollers d mounted on shafts e carried by bearings f bolted to the frame bed-"plate g;

These shafts are driven as hereinafter described and the rollers (1 drive the drum.

The ring I) is of channel section; the inner flange 6' supports one end of the grate bars h, and i which alternate with each other and form the cylindrical grate. The ringc is of a somewhat more complex section, having on its inner face a flange'k which sup orts the ends .of bars h. The bars a exten through radial slots in ring a and are held up therein by packing pieces Z bolted to the ring. Before eachpacking piece is put in place the correspondmg bar z is engaged by means of a notch a" on its edge with a ring m. This engagement causes the ring to revolve with the drum. Guide rollers n carried 'on the main casing o in diflerent vertical planes bear against the ring m, and serve to maintain it in a fixed plane which is inclined to the plane perpendicular to the axis of rotation of the drumnwith the result that as the drum revolves the bars 5 receive a reciprocatin longitudinal movement, while the bars do not move in the direction of their length. v

The feed box 12 is fixed to the main casing o eccentrically tothe drum, the object being to feed the fuel against the descending grate bars to aid the distribution of the fuel; 9' is the fuel hopper, 1- the feeding worm and s a fire tube for protecting the inner face of the casing 0.

The drive is from the main shaft t carried in bearings s on the front of the bed plate g. The bevel ear u on the shaft drives the roller sha ts e which turn the drum. A worm gear on the shaft t drives the shaft '0 of an eccentric w which gives motion to the adjustable stroke lever 41: operating the friction drive wheel y of the feeding worm r.

Openings 0' and o in the casing o serve for examination of the bars and their removal. if necessary. A casing 2 extends from the main casing-0 to the boiler brickwork and encloses the whole grate, forming a substantially air-tight chamber into which air is forced or drawn at any suitable point for combustion of the 'fuel.

Door 9' serves for removal of riddlings and ashes which fall through the grate and door 9 for removal of ashes and clinker discharged at the open end of the drum.

The speed at which a grate of this kind should be revolved in order that the fuel maybe retained by centrifugal force in its distributed condition depends on the state of subdivision of the fuel and its specific gravity. In the case of a. grate 2 ft. 6 inches in diameter burning Midland coal passed through a 1" mesh screen, 7 9 revolutions per minute were suflicient.

Having'thus described the nature of the said invention and the best means I know of carrying the same into practical effect, I claim 1. A method of burning-fuel in a rotating v grate having the shape of a figure of revolution, which comprises the step of both distributing the fuel in the form of a layer over the inner surface of the grate and retaining it against this surface, by centrifugal force due to the speed of revolution of the grate.

2; A method of burning fuel in a rotating grate having the shape of a figure of revolution which comprises the step of both distributing the fuel in the form of a'layer over the inner surface of the grate and: re-

taining it against this surface by centrifugal force due to the speed of revolution of the grate and causin air to pass inwardly through the layer of fuel.

3. A method of burning fuel in a rotating grate having the shape of a figure of revolution which com rises the step of both distributlng the fuel 1n the form of a layer over the inner surface of the grate and retaining it against this surface b centrifugal force due to the speed of revo tion of the grate,

and causing the layer to travel in the longitudinal direction of the grate during the revolution so that ashes and clinkers are discharged from the end of the grate.

4. A method of burning fuel in a rotating grate having the shape of a figure of revo lution, which comprises the step of both distributing the fuel in the form of a layer oiier the inner surface of the grate and retaining it against this surface by centrifugal force due to the speed of revolution of the grate, causing the layer to travel in the longitudinal direction of the grate during the revolution so that ashes and clinkers are discharged from the end of the grate and causing air to pass inwardly through the layer'of fuel. v

5. A method of burning fuel in a r0tat-' ing grate, having the shape of a figure of revolution which comprises feeding the fuel into the grate, and retaining it in the form of a layer against the inner surface thereof by centrifugal force due tothe speed of rev olution of the grate.

6. A method of burning fuel in a rotating grate having the shape ofa figure of revolution, which comprises feeding the fuel against the portion of the inner surface of the grate which is descending the grate, and causing air topass inwardly through the layer of fuel. 7

8. A method of burning fuel in a rotating grate having the shape of a figure of revolution, which comprises feeding the fuel against the portion of the inner surfabe of the grate which is descending in the rotational movement, retaining it in the form of a layer against this surface by centrifugal force due to the speed of revolution of the grate, and causing air to pass inwardly through the layer of fuel.

9. A method of burning fuel in a rotating grate, having the shape of a figure of revolution which comprises feeding the fuel into the grate, retaining it in the form of a layer against t e inner surface thereof by centrifugal force due to the speed of revolu-- tion of the grate, and causing. the layer of fuel-to travel in thelongitudinal direction of the grate during. the revolution so that ashes and clinkers are discharged from the end of the grate.

10. A method of burning fuel in a rotating grate having the shape of a flan-e of 1 revolution, which comprises feeding a fuel 'nwaaao grate, and causing the. layer of fuel to travel Q dinal direction of the grate during therevo- I in the longitudinal direction of the grate during the revolution so that ashes and clinkers are discharged from the end of the grate. Y

11. Aimethod of burning fuel in a rotating grate, having the shape of a' figure of revolution which comprises feeding the fuel into the grate, retaining it in the form of a layer against the inner surface thereof by centrifugal force due to the speed of rev0lution of the grate, causing air to pass inwardly through the layer of fuel and causing the layer of fuel to travel in the longitu lutio n so that ashes and-clinkers are discharged from the end of the grate.

. 12. A method of burning fuel in a rotating grate having the shape of a figure of revolution, which comprises feeding the fuel against the portion of the inner surface of the-grate which is descending in the rotational movement, retaining it 1n the formvof a layer against this surface by centrifugal force due to the speed of revolution of the grate, causing air to pass inwardly through the. layer of fuel, and causin the layer of fuel to travel in'the longitu inal direction of the grate during the revolution so that ashes and clinkers are discharged from the end of the grate.

In testimony whereof I have signed my I name to this specification.

SL MeEwErI. 

